Physicians may have discovered a way to predict which patients with severe asthma are likely to benefit from treatment with systemic corticosteroids.

With the help from a dozen clinical variables, using machine learning techniques, researchers have identified a way to predict which of their patients with severe asthma are likely to benefit from treatment with systemic corticosteroids.

Using systemic corticosteroids for severe asthma

Researchers explain how physicians already have some clues regarding which patients are most helped by corticosteroid injections or pills. But the newly identified set of variables, when processed by computer software, will yield more precise predictions of a patient’s response.

Wei Wu, a faculty member in Carnegie Mellon University‘s Computational Biology Department, USA, explains: “Systemic corticosteroids are the most effective therapy we have for asthma, but not all patients respond in the same way.

“Unfortunately, when clinicians don’t see a big improvement after initial treatment, they might give patients even higher doses. If a patient is one of those who can’t be helped by corticosteroids, the higher dose just means worse side effects.”

Dr. Sally E. Wenzel, director of the University of Pittsburgh Asthma Institute at UPMC, USA, adds: “I see so many patients in my clinic who have been ravaged by the side effects of corticosteroids.”

But are the side effects of systemic corticosteroids worth it?

Wenzel explained how weight gain, extreme emotions, inability to sleep, glaucoma and thinning of the skin are among the possible side effects of corticosteroid pills and injections, so physicians would like to prescribe them only to patients they know will benefit from them.

She emphasised that the study addresses corticosteroid pills and injections, not the widely used corticosteroid inhalers, although there is likely to be some overlap in patient response to the medications in either form.

The researchers used a machine learning algorithm to examine 100 variables for each of 346 adult patients in the federally funded Severe Asthma Research Program (SARP), in order to fully understand how different subgroups of patients respond to systemic corticosteroid therapy.

According to the researchers, the benefits of systemic corticosteroids can be substantial, so physicians likely will continue to try them initially in the treatment of severe asthma.

Let’s talk algorithms

The algorithm, developed by Wu and Seojin Bang, a Ph.D. student in CMU’s Computational Biology Department, recognises patterns in massive volumes of complex clinical data.

The system clustered patients into four subgroups, including two for severe asthmatics, one that responded to systemic corticosteroids and one that didn’t.

Of the original 100 variables, they identified 12 that could correctly categorise patients with high confidence if processed by a computer app.

To test this process, they used the 12 variables (or their equivalents) to categorise a group of 182 SARP participants not included in the original analysis.

The variables proved effective in successfully categorising these additional patients.

Wenzel further explained that once software becomes available for practitioners to predict patient response, they will likely switch to alternative therapies, rather than increase corticosteroid dosages, if patients haven’t responded and fall into the subgroup of patients that don’t usually benefit from the drugs.